965
FXUS66 KPDT 110521
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
1021 PM PDT FRI APR 10 2026
KEY MESSAGES
- SHOWER AND THUNDERSTORM CHANCES INCREASE THROUGH SATURDAY, BUT
LINGER INTO SUNDAY.
- ANOTHER SYSTEM WILL IMPACT THE REGION AROUND MIDWEEK AND COULD
BRING SOME MOUNTAIN SNOW.
- RIVERS, ESPECIALLY THE NACHES AND SOME POINTS ON THE GRANDE
RONDE ARE RUNNING HIGH.
DISCUSSION
AN UPPER LEVEL TROUGH WILL MOVE ONSHORE IN NORTHERN CALIFORNIA
THIS AFTERNOON/EVENING AS A LARGE UPPER LOW APPROACHES. THIS
UPPER LOW WILL THEN MOVE ONSHORE IN NORTHERN CALIFORNIA SATURDAY
NIGHT/SUNDAY MORNING AND MOVE EASTWARD. AS THE LOW MOVES, ITS
ASSOCIATED TROUGH WILL MOVE ACROSS THE WESTERN STATES THROUGH
MONDAY, WHICH WILL KEEP UNSETTLED WEATHER OVER THE AREA. SOME
WEAK RIDGING, THEN A MORE ZONAL FLOW WILL DRY THINGS OUT FOR
LATER MONDAY INTO TUESDAY.
SHOWERS AND ISOLATED THUNDERSTORMS (20-30 PERCENT) ARE EXPECTED
THIS AFTERNOON MAINLY OVER CENTRAL OREGON AND THE JOHN DAY
HIGHLANDS. ON SATURDAY, THERE WILL BE RAIN CHANCES JUST ABOUT
EVERYWHERE, WITH THE HIGHEST PROBABILITIES (>60 PERCENT) MAINLY
IN CENTRAL OREGON AND ACROSS THE MOUNTAINS. THUNDERSTORMS
CHANCES ARE MORE WIDESPREAD ACROSS THE AREA AS WELL THE OVERALL
PROBABILITIES STILL REMAIN GENERALLY 25 PERCENT OR LESS. AS THE
TROUGH MIGRATES EAST ON SUNDAY, THE HIGHEST RAIN (AND
THUNDERSTORM CHANCES WILL MAINLY BE OVER EASTERN OREGON AND THE
JOHN DAY HIGHLANDS.
WHILE CAPE VALUES THROUGH SUNDAY ARE SEVERAL HUNDRED J/KG IN
AREAS AND LI VALUES ARE AS LOW AS -2 TO -3 DEGREES CELSIUS.
QUESTIONS REMAIN AS TO HOW ANY CLOUD COVER AND ANY BREAKS IN
THAT CLOUD COVER WILL PLAY IN TO CONVECTIVE INITIATION.
ANOTHER LOW, THIS TIME DROPPING DOWN FROM CANADA WILL IMPACT
THE REGION AROUND MIDWEEK, BRINGING ANOTHER ROUND OF
PRECIPITATION, SOME LATE SEASON MOUNTAIN SNOW AND TEMPERATURES
ABOUT 5 DEGREES BELOW NORMAL.
LASTLY, WITH THE RAINFALL EXPECTED OVER THE NEXT FEW DAYS,
RIVERS, ESPECIALLY THE NACHES AND A FEW POINTS ON THE GRANDE
RONDE, WILL CONTINUE TO RUN HIGH AND ARE FORECAST TO REACH
ACTION STAGE. OTHER RIVERS WILL HAVE SIGNIFICANT IN-BANKS RISES
BUT WILL REMAIN BELOW ACTION STAGE.
AVIATION /06Z TAFS THROUGH 06Z SUNDAY/
LIGHT RAIN WILL CONTINUE TO DRIFT NORTH ACROSS KDLS FOR THE
NEXT FEW HOURS AND THEN TOWARD 12Z, SHOWERS COULD BE EXPANDING
ACROSS AREAS LIKE ALW/PSC AND YKM. OVERALL LIGHT WINDS (LESS
THAN 10 KNOTS) WILL BE THE RULE AT LEAST UNTIL SATURDAY
AFTERNOON WHEN CHANCES FOR THUNDERSTORMS AND LOCALLY ERRATIC
OUTFLOWS COULD BRING STRONGER GUSTS ANYWHERE FROM BDN/RDM,
NORTHEAST TO THE PDT/PSC/ALW TERMINALS (MID TO LATE AFTERNOON
AND EARLY EVENING).
PRELIMINARY POINT TEMPS/POPS
PDT 47 65 42 60 / 50 50 30 70
ALW 50 65 46 60 / 50 70 30 80
PSC 49 71 44 66 / 30 40 10 40
YKM 48 67 42 68 / 30 40 10 20
HRI 47 69 44 63 / 40 40 10 50
ELN 45 60 39 63 / 30 50 10 20
RDM 40 61 37 54 / 80 70 70 60
LGD 45 62 41 55 / 50 90 60 100
GCD 42 61 40 52 / 60 70 70 100
DLS 50 67 47 64 / 60 60 30 40
PDT WATCHES/WARNINGS/ADVISORIES
WA...NONE.
OR...NONE.
DISCUSSION...77
AVIATION...71
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page